sirolimus and Microsatellite-Instability

The treatment and prognosis of advanced colorectal cancer (CRC) remain a challenging clinical research focus. Here, we describe a new CRC tumor suppressor and potential therapeutic target: thymocyte selection associated high mobility group box (TOX) protein. The expression of TOX was lower in CRC than para-CRC. With the increase of tumor stage, TOX expression decreased, indicating the presence of TOX relates to better overall survival (OS). TOX suppressed the mechanistic target of rapamycin kinase (mTOR) signaling to inhibit cell proliferation, migration, invasion, and change the epithelial-mesenchymal transition (EMT) process. In addition, TOX promoted apoptosis. As tumor mutation burden and tumor microenvironment play vital roles in the occurrence and development of tumors, we analyzed the TOX expression in the immune microenvironment of CRC. The high TOX expression was negatively correlated with TumorPurity. Moreover, it was positively related to ImmuneScore, StromalScore, microsatellite instability (MSI) status, and Consensus Molecular Subtypes (CMS) 3 typing. Based on gene set enrichment analysis (GSEA), the reduced expression of TOX activated mTOR. We found rapamycin, a mTOR inhibitor, partly inhibited cell proliferation, invasion, and migration in shTOX HCT116 cells. Lastly, TOX suppressed tumorigenesis and lung metastasis of CRC

Topics: Aged; Animals; Apoptosis; Cell Movement; Cell Proliferation; Colorectal Neoplasms; Epithelial-Mesenchymal Transition; Female; Genes, Tumor Suppressor; HCT116 Cells; High Mobility Group Proteins; Humans; Male; Mice; Mice, Inbred C57BL; Mice, Nude; Microsatellite Instability; Middle Aged; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases; Transfection; Tumor Burden; Tumor Microenvironment; Xenograft Model Antitumor Assays

The classification of endometrial carcinoma divided into types I and II has shown clinical usefulness. Molecular alterations of PTEN and Wnt/β-catenin have been identified in this neoplasia. However, the role of mammalian target of rapamycin according to subcellular localization in the pathogenesis of this neoplasia and its prognostic significance are not well defined. We studied the expression of phosphorylated mammalian target of rapamycin, PTEN, and β-catenin and their relationship with clinicopathologic features, molecular factors (microsatellite instability, mismatch repair, and BRAF genes) and patients' survival in a series of 260 nonconsecutive endometrial carcinomas. Tissue microarrays were manually constructed, and genomic DNA was extracted from paraffin-embedded cylinders (1 mm thick) from preselected tumor areas. The mammalian target of rapamycin in the nuclei (mTORC2; 47%) or cytoplasm (mTORC1; 48%) were seen in type II endometrial carcinoma, the latter also in advanced stages (P ≤ .046). PTEN loss (58%) was detected in type I endometrial carcinoma of grade 1, at early stage, with mismatch repair gene loss (24.4%) and microsatellite instability-positive status (22%; P ≤ .05). Nuclear β-catenin (16%) was found in type I tumors of younger patients (P ≤ .003). In contrast, BRAF-V600E mutations were not detected (0%). Mammalian target of rapamycin cytoplasmic high expression implied poorer prognosis (P = .02; Kaplan-Meier, log-rank test), but grade 3 tumors, vascular invasion, advanced stage, or PTEN presence correlated independently with a negative impact on survival (all P ≤ .036; Cox analysis). Our results show that mammalian target of rapamycin, PTEN, and β-catenin are independently involved in different molecular subtypes of endometrial carcinoma with diverse patients' prognosis and support their distinctive treatment based on targeted drugs.

Topics: Adenocarcinoma; Adult; Aged; Aged, 80 and over; beta Catenin; Biomarkers, Tumor; Carcinoma, Endometrioid; DNA Mismatch Repair; DNA, Neoplasm; Endometrial Neoplasms; Female; Follow-Up Studies; Humans; Immunohistochemistry; Kaplan-Meier Estimate; Microsatellite Instability; Middle Aged; Mutation; Phosphorylation; Prognosis; PTEN Phosphohydrolase; Sirolimus; Tissue Array Analysis; TOR Serine-Threonine Kinases

High-frequency microsatellite-instable (MSI-H) tumors account for approximately 15% of colorectal cancers. Therapeutic decisions for colorectal cancer are empirically based and currently do not emphasize molecular subclassification despite an increasing collection of gene expression information. Our objective was to identify low molecular weight compounds with preferential activity against MSI colorectal cancers using combined gene expression data sets.. Three expression/query signatures (discovery data set) characterizing MSI-H colorectal cancer were matched with information derived from changes induced in cell lines by 164 compounds using the systems biology tool "Connectivity Map." A series of sequential filtering and ranking algorithms were used to select the candidate compounds. Compounds were validated using two additional expression/query signatures (validation data set). Cytotoxic, cell cycle, and apoptosis effects of validated compounds were evaluated in a panel of cell lines.. Fourteen of the 164 compounds were validated as targeting MSI-H cell lines using the bioinformatics approach; rapamycin, LY-294002, 17-(allylamino)-17-demethoxygeldanamycin, and trichostatin A were the most robust candidate compounds. In vitro results showed that MSI-H cell lines due to hypermethylation of MLH1 are preferentially targeted by rapamycin (18.3 versus 4.4 mumol/L; P = 0.0824) and LY-294002 (15.02 versus 10.37 mumol/L; P = 0.0385) when compared with microsatellite-stable cells. Preferential activity was also observed in MSH2 and MSH6 mutant cells.. Our study shows that the phosphatidylinositol 3-kinase-AKT-mammalian target of rapamycin pathway is of special relevance in mismatch repair-deficient colorectal cancer. In addition, we show that amalgamation of gene expression information across studies provides a robust approach for selection of potential therapies corresponding to specific groups of patients.

Topics: Algorithms; Antineoplastic Agents; Benzoquinones; Cell Cycle; Cell Line, Tumor; Chromones; Colorectal Neoplasms; Computational Biology; DNA Mismatch Repair; Drug Evaluation, Preclinical; Enzyme Inhibitors; Gene Expression Profiling; Humans; Hydroxamic Acids; Immunosuppressive Agents; Lactams, Macrocyclic; Microsatellite Instability; Morpholines; Phosphoinositide-3 Kinase Inhibitors; Proto-Oncogene Proteins c-akt; Sirolimus